When checking whether an instruction is contained in a liveness
boundary, a pointer to a DeadEndBlocks instance must always be passed.
When the pointer is null, it is only checked that the instruction occurs
within the direct live region. When the pointer is non-null, it is
checked whether the instruction occurs within the region obtained by
extending the live region up to the availability boundary within
dead-end regions that are adjacent to the non-lifetime-ending portion of
the liveness boundary.
Although I don't plan to bring over new assertions wholesale
into the current qualification branch, it's entirely possible
that various minor changes in main will use the new assertions;
having this basic support in the release branch will simplify that.
(This is why I'm adding the includes as a separate pass from
rewriting the individual assertions)
PrunedLiveness only knows about the live blocks and uses.
The PrunedLiveRange subclass is now responsible for updating liveness
based on both the defs and uses. This is in preparation for handling
non-SSA liveness when uses occur before the first def.
PrunedLiveness only knows about the live blocks and uses.
The PrunedLiveRange subclass is now responsible for updating liveness
based on both the defs and uses. This is in preparation for handling
non-SSA liveness when uses occur before the first def.
The API for computing simple liveness now returns a
SimpleLiveRangeSummary. Callers need to decide how to handle reborrows
and pointer escapes. If either condition exists then the resulting
liveness does not necessarily encapsulate the definition's ownership.
Fixes some number of latent bugs w.r.t. liveness clients.
This fixes ScopedAddressValue::computeLiveness in unreachable code scenarios.
For example:
%storeBorrow = store_borrow %_ to %adr
%loadBorrow = load_borrow %storeBorrow
apply %f(%loadBorrow) : $@convention(thin) (...) -> Never
Now recursively process uses of load_borrow as if they are address
uses.
Ultimately, this would be more efficiently handled by a recursive
lifetime completion utility which would fixup the load_borrow scope
before computing the store_borrow liveness.
Fixes rdar://99874173: unreachable assert "No user in LiveWithin block"
Return the AddressUseKind.
Fixes a bug in extendStoreBorrow where it was looking at an
uninitialized liveness result whenever a pointer escape was present.
First restore the basic PrunedLiveness abstraction to its original
intention. Move code outside of the basic abstraction that polutes the
abstraction and is fundamentally wrong from the perspective of the
liveness abstraction.
Most clients need to reason about live ranges, including the def
points, not just liveness based on use points. Add a PrunedLiveRange
layer of types that understand where the live range is
defined. Knowing where the live range is defined (the kill set) helps
reliably check that arbitrary points are within the boundary. This
way, the client doesn't need to be manage this on its own. We can also
support holes in the live range for non-SSA liveness. This makes it
safe and correct for the way liveness is now being used. This layer
safety handles:
- multiple defs
- instructions that are both uses and defs
- dead values
- unreachable code
- self-loops
So it's no longer the client's responsibility to check these things!
Add SSAPrunedLiveness and MultiDefPrunedLiveness to safely handle each
situation.
Split code that I can't figure out into
DiagnosticPrunedLiveness. Hopefully it will be deleted soon.
Add ScopedAddressOperand and ScopedAddressValue abstraction utilities
Introduce verification for store_borrow to validate its uses are correctly enclosed in their scope.
Include end_borrow/end_access as implicit uses while validating a borrow introducer
Add flow sensitive verifier rule for store_borrow/end_borrow pair
Make sure store_borrow is always to an alloc_stack
Make sure uses to store borrow location are via its return address only
